In the above mentioned United States patent specification, the clutch release bearing includes a manoeuvring element which is subjected to the action of a declutching fork. The bearing also includes a housing and an actuating element which is part of the housing, for acting on the fingers of a clutch diaphragm. The housing is carried on the ends of the clutch diaphragm fingers, by means of a coupling member. The actuating element of the housing is in the form of a sleeve which passes through the diaphragm. The clutch release bearing also includes a ball bearing which is fixed to the housing and which has an outer ring and an inner ring in the usual way. It is the outer ring that is fixed to the housing, the inner ring of the ball bearing being so conformed that it can be coupled disconnectably to the declutching fork through the manoeuvring element of the clutch release bearing. The manoeuvring element is movable in straight line movement along a guide tube.
This manoeuvring element includes pivoting hooking fingers. There is thus provided a clutch release bearing assembly in which the clutch release bearing is provided with a casing which is part of a primary unit of an associated apparatus such as a motor vehicle (the primary unit being for example the engine of the vehicle), in which the said primary unit includes the clutch, with the manoeuvring element of the clutch release bearing being part of a secondary unit of the same apparatus. This secondary unit typically comprises the gearbox of the vehicle, with its input shaft.
One consequence of the form of construction just described is that the ball bearing and the manoeuvring element are comparatively complicated, while the hooking fingers are liable to perturb the sliding movement of the manoeuvring element along its guide tube. In addition, since the clutch release bearing is largely carried by the clutch release mechanism, it is necessary, during assembly of the clutch release bearing by snap-fitting, to perform a large relative movement of the secondary unit of the apparatus with respect to its primary unit, in order to enable the input shaft of the gearbox to be inserted. In addition, before assembly, both the ball bearing and its housing are liable to be damaged as a result of mis-handling.